The war initiated by the attack on Pearl Harbor was World War II for the United States. On December 7, 1941, Japan launched a surprise military strike against the U.S. naval base at Pearl Harbor in Hawaii, resulting in significant loss of life and damage to the Pacific Fleet. The attack galvanized American public opinion and led to the U.S. declaring war on Japan the following day. This marked a turning point in the war, as the United States became actively involved in the conflict on both the Pacific and European fronts, ultimately contributing to the Allies' victory.